New Ways To Protect Old Sites

BOSTON
— SOME 3,600 years after she sat beside King Akhenaton as queen of Egypt, Nefertari can still draw a crowd - or so the Egyptian government hopes.

Grave robbers stole her mummy long ago, but the queen's visage still peers out from paintings on the walls of her mountainside tomb. Years of painstaking efforts have restored many of the images in the Valley of the Queens at Luxor. Soon, Cairo will open the tomb to visitors to help bolster its flagging tourist trade.

But archaeologists worry that tourists trouping through the rabbit-warren passages will speed destruction of the artwork.

From Nefertari's tomb in the dusty Egyptian desert to Civil War hulks off the United States, archaeological sites are under increasing threat. Much of it is from the natural forces of erosion, earthquake, and decay. But new high-tech tools, a growing appetite for antiquities, sprawling development, and war are also imperiling world ruins.

"The human threats are the most pressing," says Ricardo Elia, associate professor of archaeology at Boston University and editor of the Journal of Field Archaeology. In many areas, these threats have reached "crisis proportions," he says.

Recognition of the threats has led to a quiet revolution during the past 30 years in the way many archaeologists think about sites and how to explore them. Wholesale excavation has given way to digging selectively on the most-threatened sites.

Extrapolating from limited numbers of samples or structures dug up, archaeologists are able to glean information about the life and times of a site's former inhabitants while leaving much of the ruins untouched. Others sites are left alone entirely until time, money, or technology allows less-intrusive exploration.

Legal experts also are trying to strengthen international laws regarding artifacts. In June, the United Nations Environmental, Scientific, and Cultural Organization (UNESCO) held a 17-day conference in Rome that could begin to stem illegal trafficking in priceless finds.

Among other things, the new convention would allow source countries to use the courts in a receiving country to try and retrieve stolen artifacts. The pact, signed by 60 countries, requires enabling legislation to take effect. Until the end of the 1950s, "archaeology was about getting objects," says Robert Johnston, a professor of imaging science at the Rochester Institute of Technology in New York, who has been working sites in the Middle East for 20 years. "In early digs, they would throw away whatever wasn't pretty."

But that began to change with the "growing realization that while archaeological sites are natural resources, they do not regenerate," says Frank McManamon, chief archaeologist for the United States National Park Service and a delegate to the Rome meeting. "Whatever we have now, that's it. We'd better start actively protecting these things."

"There has been a massive shift in priorities," agrees Brian Fagan, a professor of anthropology at the University of California at Santa Barbara.

And a shift in techniques. Finesse is replacing the bull-in-a-china-shop approach to mapping an area once it is identified. Where teams might have gone in with bulldozers and backhoes, they now use ground-penetrating radar, magnetometers, and devices that measure changes in the ground's ability to conduct electricity.

Techniques that once relied on the decay rate of radioactive carbon-14 to gauge the age of organic material are giving way to mass spectroscopy, which requires a smaller sample size to date antiquities. And when excavation begins, great care is taken to record and study the context in which objects are found.

"Archaeologists used to empty the contents of pots," says Larry Conyers, an archaeology researcher at the University of Colorado at Boulder. Now, they carefully examine the contents for clues about the diets and habits of the people who used them.

Dr. Conyers has been working with Colorado colleague Payson Sheets on a Mayan site in El Salvador known as the Pompeii of the Western Hemisphere. The Mayan village was buried by ash when a nearby volcano erupted. By using radar to spot cornfields and the location of individual plants, the team has filled the voids the plants once occupied with dental plaster, yielding detailed "statues" of it in various stages of growth. This has given researchers insights into Mayan crop-rotation techniques.

A similar approach to a buried cacao tree led to the discovery of a fragile blossom on its trunk. The blossom only blooms at night and during the rainy season. This gave researchers a better handle on when the volcano erupted.

Yet the methods and technologies that make a conservation approach to archaeology possible also are making life easier for looters and treasure hunters.

"The looters are very successful because they know what they're doing," says Boston University's Elia. "A lot of them were trained by archaeologists in the old days of the great expeditions, like Belize and the Mayan sites. When the big university expeditions stopped, they left all these very trained workers who know where the burial sites were."

Technology is giving a particular advantage to treasure hunters seeking underwater riches. "All you need is the technology to find the sites and you're all set," he says. "You don't need to be an archaeologist. You need to know the general areas. You can do surveys with very high-tech equipment."

The Azores is one area where the clash between archaeologists and treasure hunting is likely to ring for some time to come. The islands, off the west coast of Africa, served as a key stop for galleons returning from the New World loaded to the gunwales with gold, silver, and other precious cargoes from the Americas. Many of them fell prey to pirates and foul weather and sank to depths reachable only by today's deep-sea submersibles.

To archaeologists, these ships represent a trove of information on 16th, 17th, and 18th century shipping. To treasure hunters, there is gold in those hulls. Portugal, which has an interest in perking up tourism at home and on the islands, will be the adjudicator under a 1993 law its parliament passed. Since the law was passed, several companies reportedly have applied for the rights to go after the ships.

"I don't know of a treasure-hunting operation that has successfully done things in an archaeological way. They all claim to. So you're faced with the question: What's better? Saving a site for future generations or having it ripped apart piecemeal? That's active destruction. That's the trade-off" of conservation archaeology, Elia says.

"It's very hard in the public's mind to understand the conservation ethic" in archaeology, he adds. "It's hard for some professional archaeologists. We want to dig things up. We always have. It's hard to say: No, you shouldn't."